THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE III. VOL. II. 



No. XI.— NOVEMBER, 1885. 



OI^l:c3-IIs^J^XJ .A.I^TIOXJES. 



I. — The Fossil Insects of the Primary Eocks : a Eapid Survey 



OF THE Entomological Fauna of the Paleozoic Period.^ 



By Charles Brongniaet, 



Honorary and Corresponding Member of the Manchester Geological Society. 



(PLATE XII.) 



THE fossil insects of Palaeozoic times are but little known, in con- 

 sequence of the small number of specimens which have been 

 discovered in the various Carboniferous deposits of the globe. 



Moreover, these specimens are usually imperfect, and authors 

 generally have had at their disposal only fragments of wings, the 

 soft parts of the body having probably been decomposed, leaving no 

 trace in the shales. 



The rarity and the imperfection of the specimens are the principal 

 causes why so few naturalists have taken up the study of the fossil 

 Hexapoda. 



The important discoveries, however, made since 1878, in the mines 

 of Commentry (Allier) — thanks to the devotion of the enlightened 

 Director of these mines, M. Henry Fayol — have resulted in giving 

 us more exact notions of the Insect fauna of the Coal Period. 



Whilst in Europe and North America there have been described 

 only about 120 examples, at Commentry, since 1878, 1300 have been 

 met with, of which tlae greater part is admirably preserved. Up to 

 the time of these discoveries no idea of the form of the body of these 

 Coal-insects could be given ; but I am now in a position to make 

 known the external anatomical details of the bodies of these wit- 

 nesses of bygone ages. 



The wings of insects furnish valuable information to aid in their 

 determination, but one must not always rely solely on their form 

 and neuration, for it would often result in the commission of grave 

 errors. 



It is necessary, as much as possible, to take into account the 

 characters of the body. Many authors, having had at their command 

 only wings, or fragments of wings, have sometimes been deceived in 



1 Translated andreadbefore the Manchester Geological Society, October 6th, 1885, 

 by Mark Stirrup, F.G.S., Hon. Sec. Revised and reprinted hj permission of the 

 author and translator. With a plate, from the Bulletin de la Societe des Amis des 

 Sciences Naturelles de Eouen (annee 1885, pi' semestre). 



DECADE III. — TOL. II. — NO. XI. 31 



